Method of assembling a conduit fitting

ABSTRACT

In a method of assembling a conduit fitting, a conduit fitting is provided, including a first coupling member, a second coupling member, an internal conduit gripping device disposed between said first coupling member and said second coupling member, and an external deformable structure. The first coupling member is pulled up with the second coupling member on an end portion of a conduit to engage the external deformable structure with an external surface of one of the first and second coupling members. After engaging the external deformable structure with the external surface of one of the first and second coupling members, the first coupling member is further pulled up with the second coupling member to axially compress the external deformable structure, until an amount of torque required to continue pulling up the first coupling member increases to a predetermined torque. The predetermined torque corresponds to an initial pulled-up position in which the conduit gripping device grips and seals the conduit.

RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 14/662,391, filed Mar. 19, 2015 and titled “Pull-up by TorqueFitting with Compressible Member,” which is a continuation applicationof U.S. application Ser. No. 12/671,730, filed Aug. 8, 2011 and titled“Pull-up by Torque Fitting with Compressible Member,” which is the U.S.national phase entry of PCT/US2008/072072, filed Aug. 4, 2008 and titled“Pull-up by Torque Ferrule Fitting”, which claims priority to prior U.S.Provisional Application Ser. No. 60/953,881, filed Aug. 3, 2007, thedisclosures of each of which are fully incorporated herein by reference.

BACKGROUND OF THE INVENTION

Flareless fittings have been in use for decades for conduits such astubes and pipes. A flareless fitting is used to connect or join two tubeor pipe ends or to connect a conduit end to another assembly such as atank, a valve, a manifold and so on. The applications are as varied asthe types of assemblies with which the fittings are used. One verycommon type of flareless fitting is a ferrule type fitting. In a ferruletype fitting, one or more ferrules are used to join or connect a conduitend to a fitting member, typically called a fitting body. The fittingbody may then be joined to (or be part of) another assembly. In aferrule type fitting, the ferrule or ferrules must establish a fluidtight seal, particularly under pressure, as well as adequate grip of theconduit and protection against vibration fatigue. High performancefittings, such as are available from Swagelok Company, Solon, Ohio, arecapable of withstanding pressures many times the rated pressure of thefitting without leaking, without vibration fatigue and without conduitblow out to the point that the conduit will burst before a seal iscompromised or the ferrule(s) may lose their grip on the conduit.

Ferrule style fittings have an advantage over other end connections inthat they do not rely on any special preparation of the tube or pipeend, other than low cost squaring and deburring. This is because theferrules create the seals and tube grip.

Lower cost markets, such as the automotive industry, have their ownperformance requirements for fluid connections. Most notably, automotiveassembly requires simpler assembly procedures. The automotive industryhas resisted using ferrule type fittings not only for cost reasons, butalso for assembly needs. Typical ferrule type fittings are assembled bywhat is commonly known as pull-up by turns. Two threaded components,such as a nut and body, enclose the conduit end and one or moreferrules. The assembly is first tightened to a finger tight conditionand then a prescribed number of turns, such as one and a quarter or oneand a half turns, are used to pull-up the fitting to its assembledcondition. The number of turns is carefully prescribed to prevent overtorque or inadequate pull-up. The automotive industry on the other handtypically wants to assemble parts by torque. This allows a simple torquewrench or tool to be used to make the final assembly with the assurancethat the final assembly has been properly assembled.

SUMMARY OF THE DISCLOSURE

In accordance with an inventive aspect of the disclosure, a method ofassembling a conduit fitting is contemplated. In an exemplary method, aconduit fitting is provided, including a first coupling member, a secondcoupling member, an internal conduit gripping device disposed betweensaid first coupling member and said second coupling member, and anexternal deformable structure. The first coupling member is pulled upwith the second coupling member on an end portion of a conduit to engagethe external deformable structure with an external surface of one of thefirst and second coupling members. After engaging the externaldeformable structure with the external surface of one of the first andsecond coupling members, the first coupling member is further pulled upwith the second coupling member to axially compress the externaldeformable structure, until an amount of torque required to continuepulling up the first coupling member increases to a predeterminedtorque. The predetermined torque corresponds to an initial pulled-upposition in which the conduit gripping device grips and seals theconduit.

In another exemplary method, a conduit fitting is provided, including afitting nut, a fitting body, and an internal conduit gripping devicedisposed between said fitting nut and said fitting body, wherein thefitting nut includes an external deformable structure integrally formedwith an end portion of the fitting nut. The fitting nut is pulled upwith the fitting body on an end portion of a conduit to engage theexternal deformable structure with an external surface of the fittingbody. After engaging the external deformable structure with the externalsurface of the fitting body, the fitting nut is further pulled up withthe fitting body to axially compress the external deformable structure,until an amount of torque required to continue pulling up the fittingnut increases to a predetermined torque. The predetermined torquecorresponds to an initial pulled-up position in which the conduitgripping device grips and seals the conduit.

In another exemplary method, a conduit fitting is provided, including afirst coupling member, a second coupling member, an internal conduitgripping device disposed between said first coupling member and saidsecond coupling member, and an external deformable structure integrallyformed with one of the first and second coupling members. The firstcoupling member is pulled up with the second coupling member on an endportion of a conduit to engage the external deformable structure with anexternal surface of the other of the first and second coupling members.After engaging the external deformable structure with the externalsurface of the other of the first and second coupling members, the firstcoupling member is further pulled up with the second coupling member toaxially compress the external deformable structure, until an amount oftorque required to continue pulling up the first coupling memberincreases by a predetermined amount, wherein the predetermined amountcomprises at least a factor of two. The predetermined torque increasecorresponds to an initial pulled-up position in which the conduitgripping device grips and seals the conduit.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other inventive aspects and features of the present disclosurewill become apparent to one skilled in the art to which the presentinvention relates upon consideration of the following description of theexemplary embodiments with reference to the accompanying drawings, inwhich:

FIG. 1 illustrates a longitudinal cross-section of an exemplaryembodiment of a fitting with an external deformable or compressiblestructure that facilitates pull-up by torque;

FIG. 2 illustrates a longitudinal cross-section of an exemplaryembodiment of a fitting with an internal deformable or compressiblestructure that facilitates pull-up by torque;

FIG. 3A illustrates a longitudinal cross-section of an exemplaryembodiment of a fitting with an internal deformable or compressiblestructure that facilitates pull-up by torque;

FIG. 3B illustrates the fitting of FIG. 3A in a pulled-up condition;

FIG. 4 illustrates a longitudinal cross-section of an exemplaryembodiment of a fitting with tube gripping device with an integraldeformable or compressible structure that facilitates pull-up by torque;

FIG. 5 illustrates a longitudinal cross-section of an exemplaryembodiment of a fitting with a two ferrule tube gripping device with anintegral deformable or compressible structure that facilitates pull-upby torque;

FIG. 6 illustrates a longitudinal cross-section of an exemplaryembodiment of a fitting with an external deformable or compressiblestructure that facilitates pull-up by torque;

FIG. 7 illustrates a longitudinal cross-section of an exemplaryembodiment of a fitting with an elastically deformable or compressiblestructure that facilitates remake of a fitting that is pulled up to apositive stop position;

FIG. 8 illustrates a longitudinal cross-section of an exemplaryembodiment of a fitting with an elastically deformable or compressiblestructure that facilitates remake of a fitting that is pulled up to apositive stop position;

FIG. 9A illustrates a longitudinal cross-section of an exemplaryembodiment of a fitting with an internal deformable or compressiblestructure that facilitates pull-up by torque;

FIG. 9B illustrates the fitting shown in FIG. 9A in a pulled upposition;

FIG. 10A is an illustration of a belleville washer;

FIG. 10B is an illustration of two belleville washers arranged in aseries configuration;

FIG. 10C is an illustration of two belleville washers arranged in aparallel configuration;

FIG. 11A illustrates a longitudinal cross-section of an exemplaryembodiment of a fitting with an internal deformable or compressiblestructure that maintains a grip and seal of a conduit gripping device onconduit when the fitting is disassembled;

FIG. 11B illustrates the fitting shown in FIG. 11A in a pulled upposition;

FIG. 11C illustrates components of the fitting of FIG. 11A where thedeformable or compressible structure maintains the conduit grippingdevice on the conduit when the fitting is disassembled;

FIG. 12 is a graph that illustrates nut displacement versus nut torquefor fittings that include a torque increasing mechanism;

FIG. 13A is a schematic illustration of an adjustable, non-deformablestructure for providing and indication of completed pull-up;

FIG. 13B is a schematic illustration of an adjustable, non-deformablestructure for providing and indication of completed pull-up;

FIG. 13C is a schematic illustration of an adjustable, non-deformablestructure for providing and indication of completed pull-up.

DETAILED DESCRIPTION OF THE INVENTION

While the inventions are described herein with specific reference to avariety of structural and material features, such descriptions areintended to be exemplary in nature and should not be construed in alimiting sense. For example, the exemplary embodiments are describedprimarily in terms of a stainless steel tube fitting for automotiveapplications. Those skilled in the art, however, will readily appreciatethat any one or more of the aspects and features of the invention may beused outside of the automotive industry, may be used with materialsother than stainless steel and may be used with many conduits including,but not limited to, tube or pipe. Still further, many of the exemplaryembodiments herein illustrate what is commonly known as a female-stylefitting, meaning that a female (i.e. internally) threaded componentreceives and abuts the conduit end. Many aspects of the female-styleembodiments will find application in male-style fittings as will beapparent to those skilled in the art. Similarly, many of the exemplaryembodiments herein illustrate male-style fittings. Many aspects of themale-style embodiments will find application in female-style fittings aswill be apparent to those skilled in the art. The invention will alsofind application for fitting assemblies that do not require threadedconnections between the fitting components, for example clamped orbolted fittings may be used. The invention will also find applicationfar beyond the exemplary embodiments herein as to connections that maybe made to a wide and ever expansive variety of fluid componentsincluding, but not limited to, other conduits, flow control devices,containers, manifolds and so on.

While various aspects of the invention are described and illustratedherein as embodied in combination in the exemplary embodiments, thesevarious aspects may be realized in many alternative embodiments, eitherindividually or in various combinations and sub-combinations thereof.Unless expressly excluded herein all such combinations andsub-combinations are intended to be within the scope of the presentinvention. Still further, while various alternative embodiments as tothe various aspects and features of the invention, such as alternativematerials, structures, configurations, methods, devices, software,hardware, control logic and so on may be described herein, suchdescriptions are not intended to be a complete or exhaustive list ofavailable alternative embodiments, whether presently known or laterdeveloped. Those skilled in the art may readily adopt one or more of theaspects, concepts or features of the invention into additionalembodiments within the scope of the present invention even if suchembodiments are not expressly disclosed herein. Additionally, eventhough some features, concepts or aspects of the invention may bedescribed herein as being a preferred arrangement or method, suchdescription is not intended to suggest that such feature is required ornecessary unless expressly so stated. Still further, exemplary orrepresentative values and ranges may be included to assist inunderstanding the present invention however, such values and ranges arenot to be construed in a limiting sense and are intended to be criticalvalues or ranges only if so expressly stated.

Although the various embodiments are described herein with specificreference to the fitting components being made of stainless steel, suchdescription is intended to be exemplary in nature and should not beconstrued in a limiting sense. Those skilled in the art will readilyappreciate that the invention may be realized using any number ofdifferent types of metal material for the fitting components, as well asmetal tubing materials, including but not limited to 316, 316L, 304,304L, any austenitic or ferritic stainless steel, any duplex stainlesssteel, any nickel alloy such as HASTALLOY, INCONEL, MONEL, alloy 825,alloy 625, any precipitation hardened stainless steel such as 17-4PH forexample, brass, copper alloys, any carbon or low allow steel such as1020, 1030, 1040 and 12L14 steel for example. A tube gripping device maybe case or through hardened to a ratio of at least 3.3 and preferably 4or more times harder that the hardest tubing material that the fittingwill be used with. Therefore, the tube gripping device need not be madeof the same material as the tubing itself. For example, the tubegripping device may be selected from the stainless steel material notedabove, or other suitable materials that may be case hardened, such asmagnesium, titanium and aluminum, to name some additional examples.

In this application, the terms “pull-up” or “pulled-up” simply refer toa condition of the fitting where a seal and grip is formed with aconduit. The term “initial pull-up” refers to the condition of thefitting and or the positions of the fitting components the first timethe fitting is pulled-up. The term “remake” or “remade” refers to thecondition of the fitting and/or the position of the fitting componentswhen the fitting was previously pulled-up to an initial pull-upposition, disassembled, and pulled-up again. In many of the embodimentsdisclosed below, additional axial advance of the fitting components isneeded to remake the fitting. In many of the embodiments disclosedherein, the fitting can be remade several times.

The present application discloses several embodiments of ferrule type,flareless fittings that may optionally be pulled-up to an assembledcondition by torque rather than by turns. The fittings include structurethat facilitates pull-up by torque. As illustrated by the exemplaryembodiments described below, the structure may take a wide variety ofdifferent forms. Any structure that provides an additional torque risewhen the fitting is properly pulled up may be employed. The torque risemay be sharp or otherwise detectable or observable. In an exemplaryembodiment, the structure allows the fitting to be disassembled andremade with a successful reseal and conduit grip. The structure may beconfigured to allow the fitting to be disassembled and remade multipletimes with a successful reseal and conduit grip each time the fitting isremade. In some embodiments, the structure facilitates repeated remakeby permitting additional stroke of the fitting components to furtheradvance a conduit gripping device, such as a ferrule, even if onlyslightly, each time the fitting is remade. In some embodiments, thestructure facilitates remake by including an elastically deformable orcompressible member that presses a conduit gripping device back intosealing engagement with a conduit when the fitting is remade to theinitial pull up position. In other embodiments, the structurefacilitates repeated remake by maintaining a seal between the conduitgripping device and the conduit when the fitting is disassembled, suchthat further advance of the ferrule is not required when the fitting isremade. The structure may be configured to allow the fitting to beremade with the same initial pull-up torque or the structure may causethe torque required for remakes to be greater than the initial pull-uptorque. One example of a fitting component structure that facilitatespull-up by torque and permits additional stroke is a compressible ordeformable structure defined by or used with at least one fittingcomponent. Several exemplary embodiments of fittings that may be pulledup by torque and may be disassembled and remade are described below.

FIG. 1 illustrates an embodiment of a fitting 100 with a deformable orcompressible structure 102 that facilitates pull-up by torque. Thefitting 100 includes a first fitting component 112 that may be realizedin the form of a male threaded body having external threads 114. Thefirst fitting component 112 joins or connects with a second fittingcomponent 116 that may be realized in the form of a female threaded nuthaving internal threads 118 that threadably mate with the threads 114 ofthe first component 112 when the fitting 100 is made-up or assembled.Different thread options and, alternatively, a variety of differentnon-threaded coupling designs may be used for the first and secondfitting components. For example, a clamp arrangements that includesclamping members that do not rotate relative to one another duringtightening of the clamp may be used. For example, the clamp members maybe forced toward one another by separate threaded members, by a camarrangement, by a lever arrangement, etc.

The fitting 100 further includes a conduit gripping device or assembly120. In this application, the term conduit gripping device means anydevice or assembly of components that grips and/or seals against aconduit, such as a tube or a pipe, as a result of making up the fittingto an assembly. The conduit gripping device may include any number ofcomponents, such as ferrules. Typically the conduit gripping device 120will include one or two ferrules. A conduit gripping device 120 isschematically illustrated in FIG. 1. The line 122 on the schematicillustration of a conduit gripping device 120 indicates that the conduitgripping device 120 may comprise a single ferrule, there may be twoferrules, or alternative gripping devices may be used. A wide variety ofconduit gripping devices 120 may be used. Examples of conduit grippingdevices that may be used include, but are not limited to, the tubegripping devices described in U.S. Pat. No. 5,882,050 issued on Mar. 16,1999; U.S. Pat. No. 6,131,963 issued on Oct. 17, 2000; and U.S. PatentApplication Publication No. 2005/0242582 published on Nov. 3, 2005;which are incorporated herein by reference in their entirety. The nut116 and tube gripping device 120 fit onto a conduit end T that isreceived by the body 112.

The female nut 116 has a drive surface 174 that contacts a drivensurface 162 of the conduit gripping device 120 during pull-up. The malethreaded body 112 is a generally cylindrical part centered on the axisX. The body 112 has an opening 183 adapted to receive the tube end T. Acentral bore 186 extends through the body 112 and defines a fluid flowpath. The central bore 186 may be in communication with another partsuch as a valve, tee, elbow, manifold, etc. It should be noted thatalthough the male threaded fitting component 112 is shown as a separatestand alone part, the features of the component by which it may make afluid connection with the female threaded fitting component could,alternatively, be incorporated into a bulk body such as a manifold,valve, pump, tank, and so on, commonly referred to as a fluid port.

The opening 183 may include a shoulder 190. The tube end T bottoms,possibly not initially but preferrably after pull-up, against theshoulder 190 when received by the body 112. The opening 183 may have aslight taper. If included, the slight taper may help form a seal aboutthe tube end T upon pull-up of the fitting 10. The male fittingcomponent 112 further includes a tapered surface, such as for examplefrusto-conical surface 192. The frusto-conical surface 192 forms aconduit gripping device or ferrule camming surface in the body 112 andmay be axially adjacent the forward end of the opening 183. The ferrulecamming surface is formed at an angle that may be selected to optimizethe camming action with a nose portion 134 of the tube gripping device120. In typical two ferrule and one ferrule fittings, this angle isabout twenty degrees but may be any suitable value from about tendegrees to about sixty degrees, for example, forty-five degrees.

The male threads 114 of the body 112 threadably mate with the threads118 on the female nut 116. The body 112 may be provided with toolengagement surfaces, such as hex flats, to facilitate holding the bodywhile the nut 116 is being tightened down during pull-up. Of course,pull-up involves relative axial translation between the fittingcomponents, the nut 116 and body 112, in this case effected by relativerotation between the nut and body, regardless of which fitting componentis being held and which is being turned. In a non-threaded coupling,pull-up involves relative axial translation between the two fittingcomponents by means other than two threaded components, such as forexample two components forced together by a clamping device.

The body 112 or the nut 116 may include a marking or a structure 199that may be used to provide an intrinsic gauging function to verifyproper pull-up for both pull-up by torque and pull-up by turns. Byintrinsic gauging is meant a structure or feature associated with thefitting itself (as contrasted with a separate tool or gauge) thatprovides an indication to the assembler that the fitting has beenproperly assembled and pulled up. A large variety of structures orfeatures may perform the intrinsic gauging function, some examples ofwhich are disclosed in International Application No. 03/07739 and U.S.Pat. Nos. 6,640,457 and 7,194,817, the entire disclosures of which arefully incorporated herein by reference. A gap gauge may also be used ina known manner to confirm proper pull-up of the fitting 100. In theexample illustrated by FIG. 1, the intrinsic gauging structure 199 is agap between the fitting component 112 and the deformable or compressiblemember 102 that is closed when the fitting is pulled up.

The conduit gripping component nose portion 134 is positioned at leastpartially within the camming mouth formed by the ferrule camming surface192. The driven surface 162 of the tube gripping device engages thedrive surface 174 of the nut 116. In an exemplary embodiment, when thefitting is pulled up, the tube gripping device 120 bites or indents intothe tube surface S, producing a strong tube grip and a fluid tight seal.However, an appropriate grip and seal may not necesarily involve a biteor indent.

In the example illustrated by FIG. 1, the nut 116 includes thedeformable or compressible structure 102 that causes the amount oftorque required to continue pulling-up the fitting to increase once thefitting reaches the initial pull up position. In the exemplaryembodiment, the increase in torque caused by the deformable orcompressible structure is sharp enough to provide a clear indicationthat the fitting has reached the proper initial pull up position. Thedeformable or compressible structure 102 may be formed integrally withthe nut 116, integrally with the body 112, have a portion integrallyformed with the nut and a portion integrally formed with the body,attached to the nut, attached to the body, and/or the deformable orcompressible structure 102 may be a separate component. The deformableor compressible structure 102 may be formed on an external surface ofthe male threaded body or an outer portion of the nut 116 that isradially outward of the female threads 118 of the nut 116. Thedeformable or compressible structure 102 may take a wide variety ofdifferent forms. Any structure that deforms and/or compresses whensandwiched between two members of the fitting and causes torque requiredto continue pulling up the fitting past a proper initial pull upposition to sharply increase may be used. The structure 102 may be aplastically deformable structure or an elastically deformable structure.Examples of materials that may be used for plastically deformablestructures include, but are not limited to, soft malleable metals, metaland plastic composites, metal and soft metal composites, and ductileplastics. Examples of soft maleable metals include, but are not limitedto pure elements and alloys comprising Tin, Lead, Aluminum, Zinc,Copper, Cadmium, Silver, and Gold. The soft malleable metals may becast, wrought, metal injection molded or sintered powder metal. Examplesof metal and plastic composites include, but are not limited to, metalwire or metal sheet integrated into hydrocarbon polymers, and aluminumsheet laminar sandwiched with a cross linked saturated wax. Examples ofmetal and soft metal composites include, but are not limited to, thinstainless steel wire integrated in a sufficiently pure soft copper, andtin sheet encased lead. Examples of ductile plastics include, but arenot limited to, low density polyethylene, and short linkedpolycarbonate. Examples of materials that may be used that elasticallydeform when the fitting is pulled-up include, but are not limited to,high strength metals and high strength composites. Examples of highstrength metals include, but are not limited to, austenitic, ferritic,martensitic, and duplex alloys of Iron, Titanium, Aluminum, Cobalt,Chromium, Nickel, Molybdenum, Niobium, and Tungsten. Additional examplesof high strength metals include, but are not limited to, alloys that arework hardened, age hardened, precipitate hardened, and interstitialhardened, for example by low temperature carburization. The highstrength metals may be cast, wrought, formed by metal injection moldedor sintered powder metal. Examples of high strength composites include,but are not limited to, metal alloys and high yield strength plasticsreinforced with alumina, graphite, silicon carbide whiskers, glassfiber, boron, and/or carbon nanofiber, for example alumina fiberreinforced aluminum, and carbon nanofiber reinforcedpoly-ether-ether-ketone.

In this application the term “plastically deformable structure” means astructure in a fitting that is plastically deformed when the fitting ispulled up to any position beyond a proper initial pull up position. Inone embodiment, the plastically deformable structure is not plasticallydeformed by pulling up the fitting to a proper initial pull up position.In another embodiment, the plastically deformable structure is somewhatplastically deformed by pull up to a proper initial pull up position. Aplastically deformable structure may or may not be elastically deformedby pulling the fitting up to the initial pull up position. In thisapplication, the term “elastically deformable structure” means astructure in a fitting that is elastically deformed by pulling up thefitting to a proper initial pull up position. An elastically deformablestructure may or may not be plastically deformed by pulling up thefitting to some position beyond the initial pull up position.

In the embodiment illustrated by FIG. 1 the deformable or compressiblestructure 102 is sandwiched between the surface 145 on the of the malethreaded body 112 and the surface 147 on the nut 116. When the fitting100 is pulled-up the compression or deformation of the structure 102between the surface 147 and the surface 145 causes the amount of torquerequired to continue pulling up the fitting to sharply increase.

The ability of the deformable or compressible structure 102 to becompressed or deformed to facilitate additional axial advance of thecomponents, 112, 116 allows the fitting to be remade. Each remake of thefitting 100 progresses the fitting body 112 further into the nut 116 foreach re-make, even if only slightly. In one embodiment, the deformableor compressible structure 102 is configured such that the torquerequired to remake the fitting is the same as the initial pull-uptorque. In another embodiment, the torque required to remake the fittingis greater than the torque required to initially pull up the torque. Inone embodiment, the deformable or compressible structure 102 isplastically deformed a first time when the fitting is initially pulledup by applying the initial pull-up torque and is then furtherplastically deformed by applying the same initial torque to remake thefitting 100. In one embodiment, the deformable or compressible structure102 is elastically deformed a first time when the fitting is pulled-upby applying the initial pull-up torque and is then elastically deformeda second time, to a greater extent, by applying the same initial torqueto remake the fitting. Many properties of the fitting components affectthe torque required to initially pull-up the fitting and the torquerequired to remake the fitting. As such, the material and/orconfiguration of the deformable or compressible member that allows thefitting to be remade and properly seal by applying the same torque asthe initial pull-up torque will vary, depending on the properties of thefitting components.

In one embodiment, when the deformable or compressible structure 102 isa separate member, the deformable or compressible member may beconfigured to convert existing fittings that may be pulled up only byturns of threaded components or a set axial stroke of the components tofittings that may be pulled up by turns and may optionally be pulled upby torque, simply by adding the separate deformable or compressiblemember to the fitting assembly.

FIG. 2 illustrates an embodiment of a male fitting 200 that includes aninternal structure 202 that facilitates pull-up by torque. The fitting200 includes a first fitting component 212 that may be realized in theform of a male threaded body having external threads 214 and a secondfitting component 216 that may be realized in the form of a femalethreaded nut having internal threads 218. Different thread options andnon-threaded coupling designs may be used for the first and secondfitting components. The fitting 200 further includes a conduit grippingdevice 220. The nut 216 and conduit gripping device 220 fit onto aconduit end T that is received by the body 212.

The female nut 216 has a drive surface 274 that contacts a drivensurface 262 of the conduit gripping device 220 during pull-up. The malethreaded body 212 is a generally cylindrical part centered on the axisX. The body 212 has an opening 283 adapted to receive the tube end T. Acentral bore 286 extends through the body 212. The tube end T bottomsagainst a shoulder 290 when received by the body 212.

The male fitting component 212 includes a tapered ferrule cammingsurface 292 in the body 212 that is axially adjacent the forward end ofthe counterbore 283. The ferrule camming surface 292 is formed at anangle with respect to the X axis that may be selected to optimize thecamming action with the nose portion 234 of the front tube grippingdevice 220. In typical two ferrule and one ferrule fittings, this angleis about twenty degrees but may be any suitable value from about tendegrees to about sixty degrees, for example, forty-five degrees.

The nose portion 234 of the tube gripping device 220 is positioned atleast partially within the camming mouth formed by the ferrule cammingsurface 292. When the fitting is pulled up, the tube gripping devices220 bites or indents into the tube surface S.

The body 212 and/or the nut 216 may include a marking or structure 251that may be used to provide an intrinsic gauging function to verifyproper pull-up for both pull-up by torque and pull-up by turns. In theexample illustrated by FIG. 2, the marking 251 comprises an unthreadedneck of the male nut. The marking 251 may take a wide variety ofdifferent forms and may be any combination of markings and/or structureson the body 212, and/or the nut 216.

In the example illustrated by FIG. 2, the internal compressible ordeformable structure 202 is disposed around at least a portion of theconduit gripping device 220. In another embodiment, the deformable orcompressible structure 202 is axially spaced from the tube grippingdevice. The deformable or compressible structure 202 may be formedintegrally with the nut 216, integrally with the body 212, have aportion integrally formed with the nut and a portion integrally formedwith the body, and/or the deformable or compressible structure 202 maybe a separate component. The illustrated deformable or compressiblestructure 202 comes into abutment with a surface 243 of the nut 216 whenthe fitting reaches the proper initial pull up position. In anembodiment, where the deformable or compressible structure is integrallyformed with the nut, the deformable or compressible structure 202 abutsa surface 213 of the body when the fitting reaches the proper initialpull up position. In an embodiment where the deformable or compressiblestructure 202 is a separate member, the deformable or compressiblestructure is compressed between the surfaces 243, 213 when the fittingreaches the proper initial pull up position. The deformable orcompressible structure is configured to cause the amount of torquerequired to continue pulling-up the fitting to sharply increase once thedeformable or compressible member is engaged between the body and thenut, and thereby provides an indication that the fitting is properlypulled up.

The ability of the deformable or compressible member 202 to becompressed allows the fitting to be remade. Each remake of the fitting200 progresses the nut 216 further onto the fitting body 212 for eachre-make, even if only slightly.

In one embodiment, the internal structure 202 is configured to convertan existing fitting that may be pulled up only by turns to a fittingthat may be pulled up by turns and may optionally be pulled up bytorque, by adding the separate member to the existing fitting assembly.

FIGS. 3A and 3B illustrate an embodiment of a female fitting 300 thatincludes an internal ring 302 that facilitates pull-up by torque. Thefitting 300 includes at least a first fitting component 312 that may berealized in the form of a female threaded body having internal threads314 and a second fitting component 316 that may be realized in the formof a male threaded nut having external threads 318. Different threadoptions and non-threaded coupling designs may be used for the first andsecond fitting components. The fitting 300 further includes a conduitgripping device 320. In the example illustrated by FIGS. 3A and 3B, theconduit gripping device comprises front and rear ferrules. However, theconduit gripping device 320 may comprise a single ferrule or anon-ferrule alternative. The nut 316 and tube gripping device 320 fitonto a conduit end T that is received by the body 312.

The male nut 316 has a drive surface 374 that contacts a driven surface362 of the conduit gripping device 320 during pull-up. The femalethreaded body 312 is a generally cylindrical part centered on the axisX. The body 312 has an opening 383 at a forward end 384 adapted toreceive the tube end T. A central bore 386 extends through the body 312.The female body further includes a counterbore 389 that forms a shoulder390. The tube end T bottoms against the shoulder 390 when received bythe body 312.

The female fitting component 312 further includes a tapered surface 392.The surface 392 forms a ferrule camming surface in the body 312. Theferrule camming surface is formed at an angle that may be selected tooptimize the camming action with the nose portion 334 of the frontferrule of the conduit gripping device 320. In typical two ferrule andone ferrule fittings, this angle is about twenty degrees but may be anysuitable value from about ten degrees to about sixty degrees.

The body 312 and/or the nut 316 may include a marking or structure 351that may be used to provide an intrinsic gauging function to verifyproper pull-up for both pull-up by torque and pull-up by turns. In theexample illustrated by FIGS. 3A and 3B, the marking 351 comprises anunthreaded neck of the male nut. The marking 351 may take a wide varietyof different forms and may be any combination of markings and/orstructures on the body 312, and/or the nut 316.

The nose portion 334 of a first ferrule of the conduit gripping device320 is positioned partially within the camming mouth formed by theferrule camming surface 392. The driven surface 362 of a second ferruleof the conduit gripping device engages the drive surface 374 of the nut316. When the fitting is pulled up, conduit gripping device 320 bitesand indents into the tube surface S.

In the examples illustrated by FIGS. 3A and 3B, the internal ring 302 isdisposed in the fitting body 312. The internal ring 302 may be disposedaround all or a portion of the conduit gripping device 320 or the ring302 may be axially spaced from a conduit gripping device. The ring 302abuts an interior surface 313 of the fitting body and a surface 343 ofthe nut 316. The ring 302 is made from a deformable or compressiblematerial and is configured to cause the amount of torque required tocontinue pulling-up the fitting to sharply increase after the ring 302is engaged by the fitting body 312 and the nut 316.

Referring to FIG. 3B, when the fitting 300 is pulled-up, the ring 302engages the nut 316 and the body 312 to cause the amount of torquerequired to continue pulling up the fitting to sharply increase. Thedeformability or compressibility of the ring 302 after the fitting hasreached the initial pull up position allows the fitting to be remade.Each remake of the fitting 300 further compresses or deforms the ring302 and progresses the nut 316 further into the fitting body 312 foreach re-make, even if only slightly.

In one embodiment, the internal ring 302 is configured to convert anexisting fitting that may be pulled up only by turns to a fitting thatmay be pulled up by turns and may optionally be pulled up by torque byadding the ring 302 to the existing fitting assembly, disassembling theexisting fitting and installing the ring.

FIGS. 4 and 5 illustrate embodiments of fittings 400, 500 that includeconduit gripping devices 420, 520 with integral deformable orcompressible structures 402 that facilitate pull-up by torque. Theconduit gripping device 420 comprises a single ferrule 421 and theconduit gripping device 520 comprises a front ferrule 519 and a rearferrule 521. The integral deformable or compressible structures 402 areconfigured to allow the fitting 400, 500 to be pulled up by turns or bytorque. The fittings 400, 500 each include at least a first fittingcomponent 412 that may be realized in the form of a female threaded bodyhaving internal threads 414 and a second fitting component 416 that maybe realized in the form of a male threaded nut having external threads418. Different thread options and non-threaded coupling designs may beused for the first and second fitting components. The nut 416 and tubegripping devices 420, 520 fit onto a conduit end T that is received bythe body 412.

The male nut 416 has a drive surface 474 that contacts a driven surface462 of the tube gripping device 420 during pull-up. The female threadedbody 412 is a generally cylindrical part centered on the axis X. Thebody 412 has an opening 480 adapted to receive the tube end T. A centralbore 486 extends through the body 412. The opening 489 forms a shoulder490. The tube end T bottoms against the shoulder 490 when received bythe body 412.

The female fitting component 412 further includes a tapered surface 492.The tapered surface 492 forms a ferrule camming surface in the body 412.When the fitting is pulled up, the ferrules of the tube gripping device420 or 520 bite or indent into the tube surface S.

In the examples illustrated by FIGS. 4 and 5, the integral deformable orcompressible structures 402 are disposed in the fitting body 412. Theillustrated integral deformable or compressible structures 402 aredisposed radially outward and of a main body 499 of the ferrule of theconduit gripping device. The integral deformable or compressiblestructure 402 are brought into abutment with an interior surface 413 ofthe fitting body and a surface 443 of the nut 416 when the fitting is inthe initial pull up position. The integral deformable or compressiblestructure 402 is made from a deformable or compressible material and isconfigured to cause the amount of torque required to continue pulling-upthe fitting to sharply increase after the integral deformable orcompressible structure 402 is engaged by the fitting body 412 and thenut 416. The ability of the integral structure 402 to be deformed orcompressed allows the fitting to be remade by allowing additionaladvance of the fitting components after initial pull up. Each remake ofthe fitting 400 further progresses the nut 416 further into the fittingbody 412 for each re-make, even if only slightly.

FIG. 6 illustrates an embodiment of a female fitting 600 that includesan external structure 602 that facilitates pull-up by torque. Thefitting 600 includes first fitting component 612 that may be realized inthe form of a female threaded body having internal threads 614 and asecond fitting component 616 that may be realized in the form of a malethreaded nut having external threads 618. The fitting 600 furtherincludes a conduit gripping device 620. The nut 616 and conduit grippingdevice 620 fit onto a conduit end T that is received by the body 612.

The male nut 616 has a drive surface 674 that contacts a driven surface662 of the tube gripping device 620 during pull-up. The body 612 has anopening 683 adapted to receive the tube end T. A central bore 686extends through the body 612. The female body further includes acounterbore 689 that forms a shoulder 690. The tube end T bottomsagainst the shoulder 690 when received by the body 612. The femalefitting component 612 further includes a tapered surface, surface 692.The surface 692 forms a ferrule camming surface in the body 612. A noseportion 634 of the tube gripping device 620 is positioned partiallywithin the camming mouth formed by the ferrule camming surface 692. Whenthe fitting is pulled up, the tube gripping devices 120 bites or indentsinto the tube surface S.

In the example illustrated by FIG. 6, the external structure 602 isdisposed around a neck 650 of the male nut 616. The external structure602 is deformable or compressible. The structure 602 may be formedintegrally with the nut 616, integrally with the body 612, have aportion integrally formed with the nut and a portion integrally formedwith the body, and/or the structure 602 may be a separate component. Theillustrated structure 602 abuts a surface 643 of the nut 616 in theillustrated embodiment. In an embodiment, where the structure isintegrally formed with the nut, the structure 602 abuts a surface 613 ofthe body. In an embodiment where the structure 602 is a separate member,the structure is compressed between the surfaces 643, 613. The structureis configured to cause the amount of torque required to continuepulling-up the fitting to sharply increase after the member is engagedbetween the body and the nut.

The ability of the structure 602 to be compressed and/or deformed allowsthe fitting to be remade. Each remake of the fitting 600 furthercompresses and/or deforms the structure 602 and progresses the nut 616further onto the fitting body 612 for each re-make, even if onlyslightly.

In one embodiment, when the structure 602 is a separate member, theseparate member may be configured to convert an existing fitting thatmay be pulled up only by turns to a fitting that may be pulled up byturns and may optionally be pulled up by torque.

FIGS. 7 and 8 illustrate embodiments of fittings that may provide apositive stop to indicate proper fitting pull-up and include deformableor compressible structures that facilitate remake of the fitting. In theembodiment illustrated by FIG. 7, a fitting 700 includes an elasticallydeformable structure 720 that is configured to be elastically deformedbetween a tube gripping device 702 and a fitting component 716 when thefitting 700 is pulled-up. When the elastically deformable structure 702is compressed, energy is stored in the elastically deformable structure.In the example illustrated by FIG. 7, the fitting component 716 engagesa fitting component 712 to provide an indication that the fitting isproperly pulled-up. This engagement may be a positive stop or theengagement may allow additional axial movement of the fitting component712 relatively toward the fitting component 716. When the fitting 700 isdisassembled, the elastically deformable structure 702 returns to itsoriginal, uncompressed state. When the fitting is remade to the originalpull-up position, the elastically deformable structure 702 is againcompressed. The energy stored in the elastically deformable member 702causes the elastically deformable member to apply opposite forcesagainst the tube gripping device 720 and the fitting component 716 asindicated by arrows 750. In one embodiment, the force applied by theelastically deformable member 702 causes the tube gripping device 720 toreseal with the tube end T when the fitting is at the original pull-upposition. This allows a positive stop to be provided between the fittingcomponents 712, 716, while still allowing the fitting to be remade.

In the example illustrated by FIG. 7, the elastically deformablestructure 702 is a separate component that is disposed between the tubegripping device 720 and the fitting component 716. In other embodiments,the elastically deformable structure 702 is integrally formed with thefitting component 716 and/or the tube gripping device 720. Theelastically deformable structure 702 may be made from any material andtake any configuration that allows the elastically deformable structureto apply a spring-like force to the tube gripping device 720 to causethe tube gripping device to reseal with the tube when the fitting isreassembled to the original pull-up position. The elastically deformablestructure may be a spring, such as a belleville spring. In oneembodiment, the elastically deformable structure is a belleville springthat retains its elasticity and returns to its original shape even whencompressed flat. Examples of materials that the elastically deformablestructure may be made from include the materials that are listed above.

The fitting component 712 may be a male fitting component that mateswith a female fitting component 716 or the fitting component 712 may bea female fitting component that mates with a male fitting component 716.In the example illustrated by FIG. 7, the tube gripping device 720includes two ferrules. However, the tube gripping device may compriseany number of ferrules. The tube gripping device 720 may comprise asingle ferrule, there may be two ferrules, or alternative grippingdevices may be used. The fitting component 716 and tube gripping device720 fit onto the conduit end T that is received by the fitting component712.

The fitting component 716 has a drive surface 774 that contacts theelastically compressible member 702, which in turn contacts a drivensurface 762 of the tube gripping device 720 during pull-up. The fittingcomponent 712 has an opening 783 adapted to receive the tube end T. Acentral bore 786 extends through the fitting component 712 and defines afluid flow path. The tube end T bottoms against a shoulder 790. Thefitting component 712 further includes a tapered surface 792 thatengages the tube gripping device 720 to cause the tube gripping device720 to grip and seal the tube end T.

A tube gripping device nose portion 734 is positioned at least partiallywithin the camming surface 792. The driven surface 762 of a tubegripping device engages the elastically deformable structure 702, whichengages the drive surface 774 of the fitting component 716. When thefitting is pulled up, the elastically deformable structure 702 iscompressed or deformed and applies force against the tube grippingdevice 720 to cause the tube gripping device to bite or indent into thetube surface S, producing a strong tube grip and a fluid tight seal.

In the example illustrated by FIG. 7, the fitting components 712, 716define structure 752 that causes the amount of torque required tocontinue pulling-up the fitting to sharply increase. In the FIG. 7embodiment, this structure 752 comprises surfaces 798, 799 that define apositive stop, which inhibits the fitting from being tightened beyondthe pull-up position. The structure 752 may also be configured to allowfor additional tightening and axial displacement of the components 712,716 beyond the initial pull-up position. For example, the structure mayinclude one or more inclined surfaces or a deformable or compressiblestructure that allows additional axial advance. The structure 752 may beformed integrally with the fitting component 716, integrally formed withthe fitting component 712, have a portion integrally formed with each ofthe fitting components and/or the structure may be a separate component.The structure 752 may be defined at any area of the fitting components.For example, the structure may be defined at an external surface thefitting components or internal surface of the fitting components. Thestructure 752 may take a wide variety of different forms. Any structurethat provides a tactile indication that the fitting has reached theproperly pulled-up position may be used.

In the embodiment illustrated by FIG. 8, a fitting 800 includes anelastically deformable structure 802 that is configured to beelastically deformed between a tube end T and a fitting component 812when the fitting 800 is pulled-up. When the elastically deformablestructure 802 is compressed, energy is stored in the elasticallydeformable structure. In the example illustrated by FIG. 8, a fittingcomponent 816 engages a fitting component 812 to provide an indicationthat the fitting is properly pulled-up. This engagement may be apositive stop or the engagement may allow additional axial movement ofthe fitting component 812 relatively toward the fitting component 816.When the fitting 800 is disassembled, the elastically deformablestructure 802 returns to its original, uncompressed state. When thefitting is remade to the original pull-up position, the elasticallydeformable structure 802 is again compressed. The energy stored in theelastically deformable member 802 causes the elastically deformablemember to apply opposite forces against the tube end T and the fittingcomponent 812 as indicated by arrows 850. The elastically deformablemember 802 forces the tube end T against the tube gripping device 820 toreseal the tube with the tube gripping device 820 when the fitting isremade to the original pull-up position. This allows a positive stop tobe provided between the fitting components 812, 816, while stillallowing the fitting to be remade.

In the example illustrated by FIG. 8, the elastically deformablestructure 802 is a separate component that is disposed between the tubeend T and the fitting component 812. In other embodiments, theelastically deformable structure 802 is integrally formed with thefitting component 812 and/or the tube end T. The elastically deformablestructure 802 may be made from any material and take any configurationthat allows the elastically deformable structure to apply a spring-likeforce to the tube end T to cause the tube end T to reseal with the tubegripping device 820 when the fitting is reassembled to the originalpull-up position. The elastically deformable structure may be a spring,such as a belleville spring. In one embodiment, the elasticallydeformable structure is a belleville spring that retains its elasticityand returns to its original shape even when compressed flat. Examples ofmaterials that the elastically deformable structure may be made from arelisted above.

The fitting component 812 may be a male fitting component that mateswith a female fitting component 816 or the fitting component 812 may bea female fitting component that mates with a male fitting component 816.In the example illustrated by FIG. 8, the tube gripping device 820includes two ferrules. However, the tube gripping device may compriseany number of ferrules. The fitting component 816 and tube grippingdevice 820 fit onto the conduit end T that is received by the fittingcomponent 812.

The fitting component 816 has a drive surface 874 that contacts a drivensurface 862 of the tube gripping device 820 during pull-up. The fittingcomponent 812 has an opening 883 adapted to receive the elasticallydeforming structure 802 and the tube end T. A central bore 886 extendsthrough the fitting component 812 and defines a fluid flow path. Thefitting component 812 includes a shoulder 890. The elastically deformedstructure 802 is disposed between the tube end T and the shoulder 890.

The fitting component 812 includes a tapered surface 892 that engagesthe tube gripping device 820 to cam the tube gripping device against thetube. A tube gripping nose portion 834 is positioned at least partiallywithin the camming surface 892. The driven surface 862 of the tubegripping device 820 engages the drive surface 874 of the fittingcomponent 816. When the fitting is pulled up, the tube gripping device820 bites into the tube and drives tube end T against the elasticallydeformable structure 802. The elastically deformable structure 802 iscompressed between the tube end T and the shoulder 890 of the fittingcomponent 812.

In the example illustrated by FIG. 8, the fitting components 812, 816define structure 852 that causes the amount of torque required tocontinue pulling-up the fitting to sharply increase. In the FIG. 8embodiment, this structure 852 comprises first and second surfaces 898,899 that define a positive stop, which inhibits the fitting from beingtightened beyond the pull-up position. In another embodiment, thestructure 852 may be configured to allow for additional tightening ofthe components 812, 816 beyond the initial pull-up position. Anystructure that provides a tactile indication that the fitting hasreached the properly pulled-up position may be used.

FIGS. 9A and 9B illustrate an embodiment of a fitting 900 with adeformable or compressible structure 902 that both engages a conduitgripping device 920 to bring the deformable structure 902 device intosealing engagement with the conduit and engages fitting components 912and 916 to provide a sharp rise in torque that indicates that thefitting is properly pulled-up. The conduit gripping device 920 includesa stop portion 950 and a ferrule drive arm 952. When the fitting 900 ispulled-up for a first time, the ferrule drive arm 952 advances the tubegripping device 920 until the stop portion 950 engages the fittingcomponent 912. The engagement between the stop portion 950 and thefitting component 912 causes a sharp rise in torque that indicates thatthe ferrule is properly pulled up. Referring to FIG. 9B, the ferruledrive arm 952 may be flexed with respect to the stop portion 950 asindicated by arrow 954 to allow the fitting to be remade. The flexing ofthe ferrule drive arm 952 with respect to the stop portion may causeelastic or plastic deformation of the deformable or compressiblestructure 902. In the embodiment illustrated by FIGS. 9A and 9B, thedeformable or compressible structure 902 is integrally formed with thefitting component 916. In another embodiment, the deformable orcompressible structure 902 is connected to the fitting component 916. Inanother embodiment, the deformable or compressible structure 902 is aseparate member that the fitting component 916 presses against.

The deformable or compressible structure 902 may be made from anymaterial and take any configuration that drives the tube gripping device920 into sealing engagement with the tube, provides a sharp increase intorque when the fitting is pulled-up, and allows the fitting to beremade. Examples of materials that the elastically deformable structure902 may be made from are listed above.

The fitting component 912 may be a male fitting component that mateswith a female fitting component 916 or the fitting component 912 may bea female fitting component that mates with a male fitting component 916.The tube gripping device 920 may comprise any number of ferrules orother tube gripping and/or sealing structures. The fitting component 916and tube gripping device 920 fit onto a conduit end T that is receivedby the fitting component 912.

The fitting component 916 drives the deformable or compressible member902, which in turn contacts a driven surface 962 of the tube grippingdevice 920 during pull-up. The fitting component 912 includes a taperedsurface 992 that engages the tube gripping device 920 and presses thetube gripping device into sealing engagement with the tube end T.

A nose portion 934 of the tube gripping device is positioned at leastpartially within the camming surface 992. The driven surface 962 of atube gripping device engages the deformable or compressible structure902 which is driven by the first fitting component 916. When the fittingis pulled up, the drive arm 952 of the deformable or compressiblestructure 902 applies force against the tube gripping device 920 tocause the tube gripping device to bite or indent into the tube surfaceS, producing a strong tube grip and a fluid tight seal. When the fitting900 reaches the pulled-up position, a wall 960 of the stop portion 950abuts against a wall 962 of the fitting component 912. At this point,additional axial advance of the tube gripping device 920 may only beachieved by flexing the drive arm 952 with respect to the stop portionas indicated by arrow 954 in FIG. 9B. This additional axial advanceallows the fitting to be remade.

The deformable or compressible members in the fitting embodimentsillustrated by FIGS. 1-9 may take a wide variety of different forms. Inone embodiment, the deformable or compressible members comprise one ormore belleville washers 1000. The belleville washers may be configuredto be plastically deformed during pull up of the fitting or thebelleville washers may be configured to be elastically deformed by pullup of the fitting to the initial pull up position. A single bellevillewasher may be used (FIG. 10A), multiple belleville washers may beassembled in a series configuration (FIG. 10B), multiple bellevillewashers may be assembled in a parallel configuration (FIG. 10C) ormultiple belleville washers may be assembled with some of the washers ina series configuration and some of the washers in a parallelconfiguration. FIG. 10B illustrates one series configuration whereradially inner surfaces 1002 of the washers engage one another. Inanother series configuration, radially outer surfaces 1004 engage oneanother.

FIGS. 11A and 11B illustrate an embodiment of a fitting 1100 that mayprovide a positive stop to indicate proper fitting pull-up and thatincludes a plastically deformable structure 1102 that facilitates remakeof the fitting. The plastically deformable structure 1102 is configuredto be plastically deformed around the tube gripping device 1120 when thefitting is pulled-up to the positive stop position. When the fitting1100 is disassembled, the plastically deformable structure 1102 remainsdeformed around the tube gripping device 1120 and maintains the grip andseal of the tube gripping device 1120 on the conduit. The fitting isremade by pulling the fitting up to the positive stop position toreestablish the seal between a fitting component 1112 and the tubegripping device 1120.

In the example illustrated by FIG. 11, the fitting component 1116engages a fitting component 1112 to provide an indication that thefitting is properly pulled-up. In the illustrated example, thisengagement provides a positive stop. In another embodiment, a structuremay be provided such that allows additional axial movement of thefitting component 1012 relatively toward the fitting component 1016after initial pull up.

In the example illustrated by FIG. 11, the plastically deformablestructure 1102 is a separate component that is disposed between the tubegripping device 1120 and the fitting component 1116. In anotherembodiment, the plastically deformable structure 1112 is integrallyformed with the fitting component 1116 and breaks away from the fittingcomponent 1116 when the fitting is disassembled after initial pull-up.In another embodiment, the plastically deformable structure 1102 isintegrally formed with the tube gripping device 1120. The plasticallydeformable structure 1102 may be made from any material and take anyconfiguration that allows the plastically deformable structure to deformagainst the tube gripping device 1120 and maintain the grip and seal ofthe tube gripping device with the tube when the fitting is disassembled.Examples of materials that the plastically deformable structure 1120 maybe made from are listed above.

In the example illustrated by FIGS. 11A and 11B, the fitting component1112 is a male fitting component that mates with a female fittingcomponent 1116. In another embodiment, the fitting component 1112 may beconfigured as a female fitting component and the fitting component 1116may be configured as a male fitting component. In the exampleillustrated by FIGS. 11A and 11B, the tube gripping device 1120 includestwo ferrules. However, the tube gripping device 1120 may comprise anynumber of ferrules. The tube gripping device 1120 may comprise a singleferrule, there may be two ferrules, or alternative gripping devices maybe used. The fitting component 1116 and tube gripping device 1120 fitonto a conduit end T that is received by the fitting component 1112.

In the example illustrated by FIGS. 11A and 11B, the fitting component1116 has a drive surface 1174 that contacts the plastically deformablemember 1102, which in turn contacts a driven surface 1162 of the tubegripping device 1120 during pull-up. In an alternate embodiment, a driveportion 1150 of the plastically deformable member 1102 is omitted andthe drive surface 1174 contacts the tube gripping device 1120 directly.

The fitting component 1112 has an opening 1183 adapted to receive thetube end T. A central bore 1186 extends through the fitting component1112 and defines a fluid flow path. The fitting component 1112 includesa shoulder 1190 that the tube end T bottoms against. The fittingcomponent 1112 further includes a tapered surface 1192 that engages thetube gripping device 1120.

Referring to FIG. 11A, a tube gripping nose portion 1134 is positionedat least partially within the camming surface 1194. The driven surface1162 of the tube gripping device engages the plastically deformablestructure 1102, which engages the drive surface 1174 of the fittingcomponent 1116.

Referring to FIG. 11B, when the fitting is pulled up, the drive portion1150 of the plastically deformable structure 1102 deforms around thedrive surface 1174 and applies force against the tube gripping device1120 to cause the tube gripping device to bite or indent into the tubesurface S, producing a strong tube grip and a fluid tight seal. When thefitting 1100 is pulled up, one or more portions of the tube grippingdevice 1120 move radially outward. The portion or portions that moveradially outward engage the plastically deformable structure 1102 andcause the plastically deformable structure to deform around the portionsof the tube gripping device. In the example illustrated by FIGS.11A-11C, the tube gripping device 1120 comprises a front ferrule 1119and a rear ferrule 1121. Referring to FIG. 11B, when the fitting 1100 ispulled up, a rear portion 1170 of the front ferrule 1119 and a rearportion 1172 of the rear ferrule 1121 move radially outward. The rearportion 1170 of the front ferrule 1119 and the rear portion 1172 of therear ferrule 1121 engage the plastically deformable structure 1102 andcause the plastically deformable structure to deform around the rearportions 1170, 1172.

Referring to FIG. 11C, when the fitting is disassembled, the tubegripping device 1120 is retained on the tube end T by the plasticallydeformable structure 1102 such that the grip and seal of the tubegripping device with the tube end T is maintained. When the fitting 1100is remade, a seal is formed between the tube gripping device 1120 andthe fitting component 1112. In the example illustrated by FIG. 11B, thisseal is formed between the front ferrule 1119 and the fitting component1112.

In the example illustrated by FIGS. 11A, 11B, and 11C, the fittingcomponents 1112, 1116 define structure 1152 that causes the amount oftorque required to continue pulling-up the fitting to sharply increase.In the FIG. 11 embodiment, this structure 1152 comprises a surface 1180of the fitting component 1112 and a surface 1182 of the fittingcomponent 1116 that define a positive stop. The positive stop inhibitsthe fitting from being tightened beyond the pull-up position. In anotherembodiment, the structure 1152 is configured to allow for additionalaxial advance of the components 1112, 1116 beyond the initial pull-upposition. The structure 1152 may be formed integrally with the fittingcomponent 1116, integrally formed with the fitting component 1112, havea portion integrally formed with each of the fitting components and/orthe structure 1152 may be a separate component. The structure 1152 maybe defined at any area of the fitting components. For example, thestructure 1152 may be defined by external surfaces of the fittingcomponents or by one or more internal surfaces of the fittingcomponents. In this application, an internal surface of the fittingcomponents is a surface that is not exposed or touchable from outsidethe fitting when the fitting is pulled up. The structure 1152 may take awide variety of different forms. Any structure that provides a tactileindication that the fitting has reached the properly pulled-up positionmay be used.

In many of the embodiments described in this application, the assemblerwill also notice a sharp and dramatic increase in pull-up torque. FIG.12 is a graph that illustrates a sharp increase in torque that may occurwhen one of the fittings described above is pulled up. Note that inregion A the torque rises somewhat slowly and steadily as a result ofthe tube gripping device or devices plastically deforming while bitinginto the tube T and camming against the body camming surface. When therelative positions of the fitting components cause one of the torqueincreasing arrangements disclosed above to act, however, the torque inregion B increases sharply and dramatically. For example the rate atwhich the torque required to further pull-up the fitting may increase bya factor of two or more when one of the disclosed fittings are properlypulled up. By selecting an appropriate torque value that corresponds toproper pull-up, the fitting may be pulled-up by torque rather than byturns. Thus, a simple torque wrench may be used to make-up the fitting.

In another exemplary embodiment, the fittings disclosed above aremodified such that the deformable or compressible structures thatfacilitates pull-up by torque are replaced with non-deformable ornon-compressible structures that provide a positive stop to indicatecompleted pull-up and that are adjustable to allow the fitting to beremade once or multiple times. The non-deformable or non-compressiblestructures that provide a positive stop and are adjustable to allowremakes of the fitting may take a wide variety of different forms. Anystructure that provides a positive stop or substantially a positive stopand may be adjusted to allow for additional axial advance of one or moreof the fitting components may be used.

FIGS. 13A, 13B, and 13B illustrate examples of non-deformable orsubstantially non-deformable structures 1300A, 1300B and 1300C thatprovide a positive stop and may be adjusted to allow for remakes. Thestructures 1300A, 1300B and 1300C may be employed in the fittingsillustrated in FIGS. 1, 2, 3A, 3B, 4, 5, 6 and 7 instead of thestructures 102, 202, 302, 402, 602 and 802. The structures 1300A, 1300B,and 1300C are illustrated as individual or separate components, but maybe formed integrally or be attached to other fitting components.

The structures 1300A, 1300B and 1300C are rings that are centered on alongitudinal axis X. The structures 1300A, 1300B and 1300C each includeone or more removable portions 1302A, 1302B, and 1302C. The removableportions 1302A are connected to the remainder of the structure 1300A,but are easily removable to reduce the length of the structure. Forexample, the removable portions 1302A may be glued to the remainder ofthe structure 1300A with a releasable adhesive. A releasable adhesivemay be applied to any portion of the removable portion 1302. Theremovable portions 1302B, 1304C are connected by frangible portions1306B, 1306C. The frangible portions 1306B, 1306C may be formed bymachining the structure 1300B. 1300C from a single piece of material orby welding, brazing, etc. The frangible portions 1306B are illustratedas being formed at a radially outer surface of the structure 1300B andthe frangible portions 1306C are illustrated as being formed at aradially inner surface of the structure 1300C. However, the frangibleportions may be formed at any position on the structure. The frangibleportions 1306B may or may not extend around the entire outer cylindricalsurface of the structure 1300B and the to the frangible portions 1306Cmay or may not extend around the entire inner cylindrical surface of thestructure 1300C. The removable portions 1302B and 1302C are removed bybreaking the frangible portions 1306B, 1306C.

The structures 1300A, 1300B, 1300C are engaged in the fittingsillustrated in FIGS. 1, 2, 3A, 3B, 4, 5, 6 and 7 in the same manner asthe structures 102, 202, 302, 402, 602 and 802. However, since thestructures 1300A, 1300B, 1300C are non-deformable the structures providea positive stop when the fitting is properly pulled-up. When the fittingis disassembled, one of the removable portions 1302A, 1302B, 1302C maybe removed. When the fitting is reassembled, the shortened structures1300A, 1300B, 1300C permit further axial advance of the fittingcomponents to facilitate remake of the fitting. The shortened structures1300A, 1300B, 1300C provide a positive stop at the appropriate remakeposition. In an exemplary embodiment, the fitting may be remade multipletimes in this manner. Since the structures 1300A, 1300B and 1300C arepreconfigured, the fitting manufacturer may control the axial stroke forinitial pull-up, the axial stoke for each remake, and the number ofremakes.

The invention has been described with reference to the preferredembodiments. Modification and alterations will occur to others upon areading and understanding of this specification. It is intended toinclude all such modifications and alterations insofar as they comewithin the scope of the appended claims or the equivalents thereof.

The invention claimed is:
 1. A method of assembling a conduit fitting,comprising: providing a conduit fitting including a first couplingmember, a second coupling member, an internal conduit gripping devicedisposed between said first coupling member and said second couplingmember, and an external deformable structure; and pulling up the firstcoupling member with the second coupling member on an end portion of aconduit to engage the external deformable structure with an externalsurface of one of the first and second coupling members; after engagingthe external deformable structure with the external surface of one ofthe first and second coupling members, continuing to pull up the firstcoupling member with the second coupling member to axially compress theexternal deformable structure, until an amount of torque required tocontinue pulling up the first coupling member increases to an initialpull-up torque; wherein the initial pull-up torque corresponds to aninitial pulled-up position in which the conduit gripping device gripsand seals the conduit, wherein the initial pull-up torque results from asharp increase in an amount of torque required to continue pulling upthe first coupling member, the sharp increase comprising an increase intorque by a factor of two or more.
 2. The method of claim 1 wherein theaxial compression of the deformable structure facilitates further axialadvance of the first coupling member relatively toward the secondcoupling member beyond said initial pulled-up position.
 3. The method ofclaim 2 wherein said further axial advance permits remake of saidfitting.
 4. The method of claim 1 wherein axial compression of thedeformable structure facilitates further axial advance of the firstcoupling member relatively toward the second coupling member beyond saidinitial pulled-up position, and said further axial advance permitsremake of said fitting by applying said initial pull-up torque.
 5. Themethod of claim 1 wherein the deformable structure is elasticallydeformed to provide said indication of completed pull-up.
 6. The methodof claim 1 wherein the deformable structure is plastically deformed toprovide said indication of completed pull-up.
 7. The method of claim 1wherein the deformable structure is integrally formed with one of thefirst and second coupling members.
 8. The method of claim 1 wherein thedeformable structure is a separate member, the method further comprisingassembling the deformable structure between the first and secondcoupling members.
 9. The method of claim 1, wherein the first couplingmember comprises a female threaded nut, wherein pulling up the firstcoupling member with the second coupling member comprises threadablymating the female threaded nut with the second coupling member.
 10. Themethod of claim 9, wherein the external deformable structure is integralwith the female threaded nut.
 11. A method of assembling a conduitfitting, comprising: providing a conduit fitting including a fittingnut, a fitting body, and an internal conduit gripping device disposedbetween said fitting nut and said fitting body, wherein the fitting nutincludes an external deformable structure integrally formed with an endportion of the fitting nut; pulling up the fitting nut with the fittingbody on an end portion of a conduit to engage the external deformablestructure with an external surface of the fitting body; after engagingthe external deformable structure with the external surface of thefitting body, continuing to pull up the fitting nut with the fittingbody to axially compress the external deformable structure, until anamount of torque required to continue pulling up the fitting nutincreases to an initial pull-up torque; wherein the initial pull-uptorque corresponds to an initial pulled-up position in which the conduitgripping device grips and seals the conduit, wherein the initial pull-uptorque results from a sharp increase in an amount of torque required tocontinue pulling up the first coupling member, the sharp increasecomprising an increase in torque by a factor of two or more.
 12. Themethod of claim 11 wherein axial compression of the deformable structurefacilitates further axial advance of the fitting nut relatively towardthe fitting body beyond said initial pulled-up position, and saidfurther axial advance permits remake of said fitting by applying saidinitial pull-up torque.
 13. The method of claim 11 wherein thedeformable structure is elastically deformed to provide said indicationof completed pull-up.
 14. The method of claim 11 wherein the deformablestructure is plastically deformed to provide said indication ofcompleted pull-up.
 15. A method of assembling a conduit fitting,comprising: providing a conduit fitting including a first couplingmember, a second coupling member, an internal conduit gripping devicedisposed between said first coupling member and said second couplingmember, and an external deformable structure integrally formed with oneof the first and second coupling members; and pulling up the firstcoupling member with the second coupling member on an end portion of aconduit to engage the external deformable structure with an externalsurface of the other of the first and second coupling members; afterengaging the external deformable structure with the external surface ofthe other of the first and second coupling members, continuing to pullup the first coupling member with the second coupling member to axiallycompress the external deformable structure, until an amount of torquerequired to continue pulling up the first coupling member increases byat least a factor of two; wherein the torque increase corresponds to aninitial pulled-up position in which the conduit gripping device gripsand seals the conduit.